Synthesis and Characterization of Selenium-Enterolycin-A Nanohybrid System and Its Promising Biological Activities

B acteriocins are proteinaceous substances with a broad range of bioactive characteristics that are produced by various bacteria. However, the limited use of bacteriocin is due to its low yield and short stability. Enterolycin-A, a type of enterocin (bacteriocin produced by Enterococcus), was extracted and purified from the Enterococcus faecium SMAN_Baghdad strain. The objective of this study was to synthesize an enterolycin-A conjugate with selenium nanoparticles to form a novel nanohybrid system that may increase the bioactivity of enterolycin-A and overcome these hurdles. The nanohybrid system was characterized via FTIR, XRD, TEM, SEM, and EDX. The Fourier transform infrared (FTIR) results indicate the presence of biological moieties, and the crystallite size was calculated to be 15.29 nm via X-ray diffraction (XRD). The shape and size of the Se-enterolycin-A nanohybrid were determined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX) confirmed the presence of selenium and protein (carbon, sulfur, and nitrogen). As a result, the Se-enterolycin-A nanohybrid showed strong antibacterial activity against MDR bacteria (Staphylococcus aureus, Streptococcus mutans, Pseudomonas aeruginosa, and Acinetobacter baumannii) according to agar well diffusion methods, MIC and MBC measurements, and antibiofilm measurements. In addition, compared with enterolycin-A alone, the Se-enterolycin-A nanohybrid exhibited promising antioxidant activity with the DPPH compound.